Valve cap gauge



Dec. 18, 1951 R. L. MERCER VALVE CAP GAUGE Filed April 12, 1949 INVENTOR. F4 YMO/V0 A. M50056 Patented Dec. 18, 1951 UNITED STATES PATENT OFFICE 3 Claims.

This invention relates to air pressure gauges, and more particularly to a tire pressure gauge for attachment to the valve stem of the tire.

It is an object of this invention to provide a valve cap gauge which will be engaged on the threaded end of the valve stem of a tire in the manner of a valve cap, to be supported thereon during the use of the tire for indicating that the air pressure in the tire is up to a selected value.

Another object of this invention is to provide a valve cap gauge which may be made in various sizes for application to the various sized tires in general commercial use.

Another object of this invention is to provide a valve cap gauge of the kind to be more particularly described hereinafter, which is transparent so that the condition of the gauge and the tire pressure indicated thereby may be readily viewed at all times by persons interested in the condition of the tire.

Still another object of this invention is to provide a light-Weight valve cap gauge of this .kind which is light in weight, strong in construction and formed of a minimum number of parts, whereby the device may be manufactured and sold at a low price.

A further object of this invention is to provide a valve cap gauge of this kind which normally holds the valve in a balanced condition between open and closed, and the arrangement of the valve cap is such that upon damage or breaking of the cap, the valve will be free for movement to the closed position as affected by the pressure in the tire.

With the above and other objects in view, my

invention consists in the arrangement, combination and details of construction disclosed in the drawings and specification, and then more particularly pointed out in the appended claims.

In the drawings:

Figure 1 is a side elevation of a valve cap gauge constructed according to an embodiment of my invention, applied to the valve stem of a tire or tube, the tire or tube being shown partly broken away and partly in section;

Figure 2 is a transverse section of the valve cap gauge applied to the valve stem, the gauge being shown in the fully balanced condition with the valve closed;

Figure 3 is an enlarged transverse section showing the piston in the lowered position holding the valve open; I

Figure 4 is a horizontal section taken on the line 4--4 of Figure 3. Referring to the drawings, the numeral I0 designates generally a valve cap gauge for indicating the air pressure in a tire or tube, the gauge also forming a valve cap for the stem of the tire. The valve cap gauge is adapted to be threadably engaged on the upper threaded end of the valve stem I I, normally provided inwthe formation and structure of a tube or tire I2.

The valve I4 in the valve stem II is of the conventional structure having a valve core I5 spring-pressed upwardly to the valve-closing poopening from the, lower end thereof. The lower end of the body I6 is formed with a threaded recess I9 having a diameter slightly greater than the diameter of the bore I8 to provide a shoulder at the lower end of the reduced-diameter bore I8 and the upper end of the recess I9. A looped spring 23 is engaged in the recess I9, engaging the shoulder 20, and is formed with an inwardlyextending arm downturned at the axial center of the recess I9 for engagin the upper end of the valve core. The body I6 is adapted to be threaded onto the upper threaded end of the stem II until the extreme upper end of the stem I I abuts the shoulder 20. In order to provide for a secure seal between the cap I6 and the stem II, I have provided a washer 2| made of rubber or other suitable compressible material, which will be seated on the shoulder 20 and engage the upper end of stem II in the threaded engagement of the body I6 on the stem.

A plug or piston 22 is slidable in the bore I8 and formed with a reduced-diameter lower end 7 24 having a diameter substantially equal to the in Figure 3 of the drawings. 3| is formed in the extreme upper end of the body I 6, and a screw 32 is-rotatably supported in' the upperwalLII, the head 34 of the screw being seated in the recess 3|. A nut 35 is fixed on the upper end of the spring 21 and threadably engaged with the bolt or screw 32. The bolt 32 provides for the adjustment of the spring tension of the spring 21 for selectively varying and controlling the spring tension which presses the piston 22 downwardly in the body [6 for engagement with the valve core l5.

In the use and operation of the valve cap gauge 10, the body 16 is threadably engaged on the threaded upper end of the valjrehstein ll. With pressure in the tire or tube I2, the valve core I5 is normally pressed to the raised position, as shown in Figure 2 of the drawings. As the cap I is completely engaged with the'stem II, the arm 25 will engage the upper end of the core IS. The tension of trresprmgzw has been adjusted to hold the pistoii' 22 downward in the body l6 against the air pressure until the air pressure in the tire exerts a selecte'dforce upwardly on the piston 22 substantially equal "to the spring tension forcing-the piston 2 2 downwardly.

When the'air pressure in"the'-tire -I"2-' is equal toor slightly g'reater than the -spring tension of the spring-27, the 'airpres'sure"wilrforce the* piston 2'2u'pwa'rdly against th'etension of the spring and the plug 'or biston22- will benioved upwardly from its seated position on the invvard extension'of the gasket 2|.

An index mark '35, which maybeforxn'ed as 'an inset ring about "the body ltfisadaptedto beaIigned with arperipheral rubber washersa cating that "the air Dfe'S Sfifih' the "tife l's'ediial "t0 "the eIctd and adjusted spl in'g tension.

3 3 with the inside Wall Of the body Hi Wilfhdld the piston 22 againstfloose -slidin movement.

-or washer 2!, will be disposed *-in such -a--m-anner that the upper end' of the ;piston will be above the index mark.

-In the use of a tire having-a-valvecapegauge of this kind; if the -valve cap gauge'should become damaged, the arm -25 would be moved out of engagement with *the core' I 5 so -that the air pressure willbiasthe-core 15 --to th'e valve-closing position. i

I do not mean to confine myself to the-exact details 'of -construction -herein disclosed, --but claim all variations-falling within the purviewof the appended claims.

I claim:

1. An air pressure indicating device for "at- V 'tachment to the valve ste'm'of -a =tire oniprisabutting the upper end of said valve -stem/anannular gasket-s'eated -on said shoulder and extending inwardly thereof, an annular -member engaged 'between said gasket and said shoulder,

- a radial extension on" said "annular member havin a-dependingend engageable with the -'valve core in'the stem for depressing -the valve and holding thevalve-openpapiston slidable in said bore and no'rmally seated "on the inward e'xtension of said gasket, a spring in-said body urging said piston downwardly-to said=seated posie ipressiire in a pneumatic tire comprising a transparent cylindrical sleeve having a closed end "and an open internally threaded end, said "threaded end being threadingly engageable on the-valve stem of the tire, an internal shoulder --formed on said sleeve for limiting the threadedinovemeiit'of the sleeve on the stem, a gasket "interposedb'e'twe'en the end of the valve stem and the shoulder, a member clampingly engaged between the gasket and the shoulder, a radial extension on said member terminating in a depending end, -'said end being axiallyaligned" with and engaging the valve in the valve stem for-depressin the valveand holding it unseated, a' pi ton woi' king in-said "sleeve and havin its lower 'face normally flush with the shoulder, anin- -dicating marking formed on the exterior "o f the 1 sleeve and registering in coincidence viththe "piston the s'ele'cted' air -pressure ofthe tire, a spring bearing on the upper-face of thepiston for retaining the piston {in its normal position against the pressure "of the air acting on" its "lower face, an anchoring and adjusting screw disposed through the closedend of thesle'eve, and amounting member for the spring "carried bythe innerend of the screw. 7

""3f lvleans for physically indicating "the "air pressure in a pneumatic tirecoznprisihg a transpa'r' e'ntcylind'rical sleev'e having a closed"end' and "an o en internally threaded "end, said threaded end being threadingly engageable'bmthevalve stem of the 'tire; an internal "shoulderform'ed on said "sleeve for limiting the threaded rnovement *o'f the sleeve on the "stem, 'agas'ket interposed between the 'end of thewalve stem"and "the shoulder; a member clampingly'i engaged between the gasket and the shoulder,"'a' radialfextension on said membertermmating in a depending end,

ing "thevalve in the valve stemior-de'prsing "thevalve and holding it unseated apistonlworki'ngin said sleeve and havin its'lowerfacernon rn'ally "flush with the shoulder, an indicating marking formed on'the'ex'terior ofthe sleeve and registering in coincidence with thespiston the selected aif'pfessure of the tire, spring bearing 'on the "upp'er face ofthep'iston 'tor retainingthe "piston in its-normal position against "the vpressure' of the an acting 'onits" lower-face, "an 'anchdiing and adjusting screw disposed through the closed end of the sleeve, a mounting member'i'or' the spring 'carrie'dby the inner end of thesor'e'w, and a concave exterior recess in said closednd receiving the outer end .of '-the screw.

' Y R'AYMOND L. ?MERCER.

- REFnRENoEs-oITEn "The ic illo wing refeiences' are of record in--the file of this patent:

UNITED sTATEs PATENTS 

